大港油田页岩油水平井钻井关键技术

Key Technologies for Drilling Horizontal Shale Oil Wells in the Dagang Oilfield

大港油田沧东凹陷页岩油水平井钻井过程中面临着破岩效率低、井眼轨迹控制难度大、摩阻扭矩大、完井管柱下入困难等技术难题,影响了页岩油的勘探开发效益。为了解决这些问题,进行了激进式水力参数设计、异形齿PDC钻头研制、深层水平段高效钻井技术、旋转导向井眼轨迹控制技术、强抑制强封堵高性能水基钻井液技术和旋转引鞋+旋转下套管工艺等技术攻关研究,形成了大港油田页岩油水平井钻井关键技术。该技术在13口页岩油水平井进行了现场应用,平均机械钻速13.16 m/h,钻井完井周期50.62 d,井下故障时效低于0.1%,均创造了大港油田的钻井纪录。研究与应用表明,大港油田页岩油水平井钻井关键技术为沧东凹陷页岩油高效勘探开发提供了技术支撑,也为国内页岩油水平井安全高效钻进提供了借鉴。

During the drilling of shale oil horizontal wells in Cangdong Sag of Dagang Oilfield,technical challenges such as low rock breaking efficiency,difficult borehole trajectory control,large friction torque and difficulty in completion string RIH were encountered,which compromised the exploration and development benefits of shale oil.To solve the problem,technical research was conducted which included the following:aggressive hydraulic parameter design,special-shaped tooth PDC bit development,deep horizontal section efficient drilling,rotary steering borehole trajectory control,strong inhibition/sealing high-performance water-based drilling fluid,and rotary guide shoe+rotary casing RIH.Together,they form a set of key shale oil horizontal well drilling technologies in Dagang Oilfield.Those technologies were applied in 13 shale oil horizontal wells,the average ROP of 13.16 m/h,drilling/completion period of 50.62 d and the downhole downtime rate of less than 0.1%were successfully achieved.The combined parameters set new records in well drilling in the Dagang Oilfield.The research and field application suggest that those key technologies have provided technical supports for the efficient exploration and development of shale oil in the Cangdong Sag,and they are of importance guidance for the safe and efficient drilling of horizontal shale oil wells in China.